1. Field of the Invention
The present invention relates to a laminate type evaporator with an expansion valve for use with a cooling cycle of an air conditioning device for an automobile.
2. Description of the Prior Art
The laminate type evaporator for use with the cooling cycle of the air conditioning device for the automobile has been recently increased since it is superior in a heat exchanging performance to the other type evaporators (fin and tube type and serpentine type, etc.).
Generally, an evaporator body of the laminate type evaporator is provided with an expansion valve, (Japanese Utility Model Publication SHO 57(1982)-47586). The evaporator body is formed by combining a pair of flat plates having an expanded portion with each other to form a flat sheet tube, and alternately laminating a plurality of the sheet tubes and heat transfer fins.
Each sheet tube is formed at its upper and lower end portions with tank portions communicated with each other. A refrigerant is temporarily stored and mixed in the tank portions. . A refrigerant passage for feeding the refrigerant is formed at the intermediate portion between the upper and lower tank portions.
An inlet pipe for inducing the refrigerant into the evaporator body is connected to the lower tank portion, and an outlet pipe for discharging the refrigerant from the evaporator body is connected to the upper tank portion. The inlet pipe is provided with an expansion vale for restricting and expanding the refrigerant,, and a conduit for connecting the evaporator body with a compressor is connected to the outlet pipe.
The expansion valve serves to control a flow rate of the refrigerant flowing in the evaporator body according to a heat load to be applied to the evaporator body. After heat exchanging in the evaporator body, the expansion valve detects the temperature and pressure of the refrigerant to be discharged from the outlet pipe and control opening degree of the valve.
Namely, the outlet pipe is provided with a thermo-sensing cylinder for sensing the temperature of the refrigerant and a pressure inducing portion for extracting the pressure of the refrigerant flowing therethrough. Both the thermo-sensing cylinder and the pressure inducing portion are communicated with the expansion valve by capillary tubes, thus effecting the sensing of temperature and the induction of pressure.
In assembling the evaporator with the expansion valve, it is necessary to connect the expansion valve with the inlet pipe, connect the thermo-sensing cylinder with the outlet pipe, form the pressure inducing portion in the outlet pipe, and connect the pressure inducing portion through the capillary tube to the expansion valve, for example. Thus, much labor is disadvantageously needed so as to complete the evaporator. Furthermore, as the expansion valve is mounted to a usual evaporator is located at a portion where the air flows, the expansion valve itself hinders the air flow, and there is a possibility of the heat exchanging performance being reduced.
Japanese Patent Laid-Open SHO 59(1984)-225702 discloses an evaporator wherein the expansion valve as mentioned above is directly mounted to the sheet tube on the side end of the evaporator. In this construction, the box-like expansion valve projects from the substantially rectangular evaporator body, causing a large size of the evaporator as a whole and rendering the installation of the evaporator disadvantageous in the viewpoint of space. Particularly in the air conditioning device for the automobile requiring to install the evaporator in a small space, such a large size of the evaporator is undesirable.